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User manual – LevelOne ProCon GSW-2690 User Manual

Page 131

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User Manual

Publication date: June, 2005

Revision A1

127

Function name:

T-Type TOS

Function description:

IP TOS Priority affect TOS fields of IP header, you can find it has 8-bit
SERVICE TYPE field that specifies how the datagram should be handled. The
field could be divided into six subfields as follows, PRECEDENCE (3 bits), D-
Type (Delay Priority, 1 bit ), T-Type (Throughput Priority, 1bit), R-Type
(Reliability Priority, 1bit ), M-Type (Monetary Cost Priority, 1bit ), and UNUSED.
PRECEDENCE 3-bits can arrange 8 kinds of priorities corresponding to the
0~7 priority in the following priority diagram. TOS Delay Priority Mapping
works while T-TYPE in TOS field of IP header of the packets received by the
switch is configured.

Parameter description:

TOS Throughput Priority Mapping:

Each Priority can select any of Queue 0 ~ Queue 3. In Default, Priority 0
is mapping to Queue 0, Priority 1 is mapping to Queue 0, Priority 2 is
mapping to Queue 1, Priority 3 is mapping to Queue 1, Priority 4 is
mapping to Queue 2, Priority 5 is mapping to Queue 2, Priority 6 is
mapping to Queue 3, and Priority 0 is mapping to Queue 3.

Fig. 3-65